#include <linux/capability.h>
#include <linux/syscalls.h>
#include <linux/memcontrol.h>
+#include <linux/poll.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
long total_swap_pages;
static int least_priority;
-static bool swap_for_hibernation;
-
static const char Bad_file[] = "Bad swap file entry ";
static const char Unused_file[] = "Unused swap file entry ";
static const char Bad_offset[] = "Bad swap offset entry ";
static DEFINE_MUTEX(swapon_mutex);
+static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait);
+/* Activity counter to indicate that a swapon or swapoff has occurred */
+static atomic_t proc_poll_event = ATOMIC_INIT(0);
+
static inline unsigned char swap_count(unsigned char ent)
{
return ent & ~SWAP_HAS_CACHE; /* may include SWAP_HAS_CONT flag */
nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
if (nr_blocks) {
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, 0);
if (err)
return err;
cond_resched();
nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, 0);
if (err)
break;
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER))
+ nr_blocks, GFP_NOIO, 0))
break;
}
if (offset > si->highest_bit)
scan_base = offset = si->lowest_bit;
- /* reuse swap entry of cache-only swap if not hibernation. */
- if (vm_swap_full()
- && usage == SWAP_HAS_CACHE
- && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ /* reuse swap entry of cache-only swap if not busy. */
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
int swap_was_freed;
spin_unlock(&swap_lock);
swap_was_freed = __try_to_reclaim_swap(si, offset);
spin_lock(&swap_lock);
if (nr_swap_pages <= 0)
goto noswap;
- if (swap_for_hibernation)
- goto noswap;
nr_swap_pages--;
for (type = swap_list.next; type >= 0 && wrapped < 2; type = next) {
return (swp_entry_t) {0};
}
+/* The only caller of this function is now susupend routine */
+swp_entry_t get_swap_page_of_type(int type)
+{
+ struct swap_info_struct *si;
+ pgoff_t offset;
+
+ spin_lock(&swap_lock);
+ si = swap_info[type];
+ if (si && (si->flags & SWP_WRITEOK)) {
+ nr_swap_pages--;
+ /* This is called for allocating swap entry, not cache */
+ offset = scan_swap_map(si, 1);
+ if (offset) {
+ spin_unlock(&swap_lock);
+ return swp_entry(type, offset);
+ }
+ nr_swap_pages++;
+ }
+ spin_unlock(&swap_lock);
+ return (swp_entry_t) {0};
+}
+
static struct swap_info_struct *swap_info_get(swp_entry_t entry)
{
struct swap_info_struct *p;
if (page_swapcount(page))
return 0;
+ /*
+ * Once hibernation has begun to create its image of memory,
+ * there's a danger that one of the calls to try_to_free_swap()
+ * - most probably a call from __try_to_reclaim_swap() while
+ * hibernation is allocating its own swap pages for the image,
+ * but conceivably even a call from memory reclaim - will free
+ * the swap from a page which has already been recorded in the
+ * image as a clean swapcache page, and then reuse its swap for
+ * another page of the image. On waking from hibernation, the
+ * original page might be freed under memory pressure, then
+ * later read back in from swap, now with the wrong data.
+ *
+ * Hibernation clears bits from gfp_allowed_mask to prevent
+ * memory reclaim from writing to disk, so check that here.
+ */
+ if (!(gfp_allowed_mask & __GFP_IO))
+ return 0;
+
delete_from_swap_cache(page);
SetPageDirty(page);
return 1;
#endif
#ifdef CONFIG_HIBERNATION
-
-static pgoff_t hibernation_offset[MAX_SWAPFILES];
-/*
- * Once hibernation starts to use swap, we freeze swap_map[]. Otherwise,
- * saved swap_map[] image to the disk will be an incomplete because it's
- * changing without synchronization with hibernation snap shot.
- * At resume, we just make swap_for_hibernation=false. We can forget
- * used maps easily.
- */
-void hibernation_freeze_swap(void)
-{
- int i;
-
- spin_lock(&swap_lock);
-
- printk(KERN_INFO "PM: Freeze Swap\n");
- swap_for_hibernation = true;
- for (i = 0; i < MAX_SWAPFILES; i++)
- hibernation_offset[i] = 1;
- spin_unlock(&swap_lock);
-}
-
-void hibernation_thaw_swap(void)
-{
- spin_lock(&swap_lock);
- if (swap_for_hibernation) {
- printk(KERN_INFO "PM: Thaw Swap\n");
- swap_for_hibernation = false;
- }
- spin_unlock(&swap_lock);
-}
-
-/*
- * Because updateing swap_map[] can make not-saved-status-change,
- * we use our own easy allocator.
- * Please see kernel/power/swap.c, Used swaps are recorded into
- * RB-tree.
- */
-swp_entry_t get_swap_for_hibernation(int type)
-{
- pgoff_t off;
- swp_entry_t val = {0};
- struct swap_info_struct *si;
-
- spin_lock(&swap_lock);
-
- si = swap_info[type];
- if (!si || !(si->flags & SWP_WRITEOK))
- goto done;
-
- for (off = hibernation_offset[type]; off < si->max; ++off) {
- if (!si->swap_map[off])
- break;
- }
- if (off < si->max) {
- val = swp_entry(type, off);
- hibernation_offset[type] = off + 1;
- }
-done:
- spin_unlock(&swap_lock);
- return val;
-}
-
-void swap_free_for_hibernation(swp_entry_t ent)
-{
- /* Nothing to do */
-}
-
/*
* Find the swap type that corresponds to given device (if any).
*
}
filp_close(swap_file, NULL);
err = 0;
+ atomic_inc(&proc_poll_event);
+ wake_up_interruptible(&proc_poll_wait);
out_dput:
filp_close(victim, NULL);
}
#ifdef CONFIG_PROC_FS
+struct proc_swaps {
+ struct seq_file seq;
+ int event;
+};
+
+static unsigned swaps_poll(struct file *file, poll_table *wait)
+{
+ struct proc_swaps *s = file->private_data;
+
+ poll_wait(file, &proc_poll_wait, wait);
+
+ if (s->event != atomic_read(&proc_poll_event)) {
+ s->event = atomic_read(&proc_poll_event);
+ return POLLIN | POLLRDNORM | POLLERR | POLLPRI;
+ }
+
+ return POLLIN | POLLRDNORM;
+}
+
/* iterator */
static void *swap_start(struct seq_file *swap, loff_t *pos)
{
static int swaps_open(struct inode *inode, struct file *file)
{
- return seq_open(file, &swaps_op);
+ struct proc_swaps *s;
+ int ret;
+
+ s = kmalloc(sizeof(struct proc_swaps), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ file->private_data = s;
+
+ ret = seq_open(file, &swaps_op);
+ if (ret) {
+ kfree(s);
+ return ret;
+ }
+
+ s->seq.private = s;
+ s->event = atomic_read(&proc_poll_event);
+ return ret;
}
static const struct file_operations proc_swaps_operations = {
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
+ .poll = swaps_poll,
};
static int __init procswaps_init(void)
p->flags |= SWP_SOLIDSTATE;
p->cluster_next = 1 + (random32() % p->highest_bit);
}
- if (discard_swap(p) == 0)
+ if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD))
p->flags |= SWP_DISCARDABLE;
}
swap_info[prev]->next = type;
spin_unlock(&swap_lock);
mutex_unlock(&swapon_mutex);
+ atomic_inc(&proc_poll_event);
+ wake_up_interruptible(&proc_poll_wait);
+
error = 0;
goto out;
bad_swap:
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff